Gear finisher with force measurement

ABSTRACT

A gear finishing machine in which a work gear is rolled in tight mesh with a gear finishing tool, and in which means are provided for measuring the resultant force acting directly between the gear and tool. The force measurement means includes an indicator which is also capable of measuring wear on the gear finishing tool, associated with signal means warning when tool wear requires dressing of the tool.

[19] 1111 .76 19 Anthony et al. @121. 16, 1973 GEAR FINHSHER WITH FORCE 1,305,878 6/1919 Carpmael 51/165.77

MEASUREMENT 1,252,478 1/1918 Noyes 51/52 3,054,225 9/1962 Praeg 51/26 X [75] Inventors: Russell W. Anthony, Carl 1H.

Motz, both of Harper Woods; Richard W. Te h, (j p im Primary Examiner-Harold D. Whitehead Woods, all f Mi h Attorney-Charles R. McKinley et al. [73] Assignee: Lear Siegler Inc., Santa Monica, Calif. [22] Filed: July 6, 1971 [57] ABSTRACT [21] Appl' 9:734 A gear finishing machine in which a work gear is rolled in tight mesh with a gear finishing tool, and in [52] us. Cl 51/52 R, 51/164.74, 5 1 164.87 which means are p d f r measuring the resultant 51 1111.131 824m s/on force acting directly between the gear and The [58] Field of Search 51/26, 52, 165 R, force as r m nt ns includes an indicator which 5 l/165.77, 165,74, 165,37 is also capable of measuring wear on the gear finishing tool, associated with signal means warning when tool References Cited wear requires dressing of the tool.

UNITED STATES PATENTS 2,885,830 s/1959 Watt....-. 51/26 27 (353M514 Drawing Figures o o H N PAIENTED 3,765,129

- SHEET 20F 3 INVENTORS.

@ unm 1 51915 SHEET 3 m= 3 WW IHUIQ- I GEAR FINISIIER WITH FORCE MEASUREMENT BRIEF SUMMARY OF THE INVENTION The present invention is intended primarily for use in conjunction with a gear honing machine but certain aspects may be used in gear shaving or rolling. In honing gears, the tool is in the form of a gear conjugate to the work gear and having teeth portions formed of a suitable yieldable resin containing abrasive particles. The honingoperation is generally applied to hardened gears and is effective to remove nicks and burrs as well as to improve the finish generally.

Since the operation is essentially abrading, the teeth of the hone undergo constant wear. The operation is carried out with the hone and gear in tight mesh and under carefully controlled pressure conditions. Accordingly, as the teeth of the hone wear, the minimum center distance between the hone and successive gears diminishes until eventually it becomes necessary to dress the bone to reduce the outside diameter of the hone, or in other words, to reduce the tooth height thereof.

The resultant radial force acting directly between the engaged portions of the gear and hone isdetermined by the difference between the force applied to the movable bone or gear support, and that part of the motive force necessary to initiate movement thereof. This resultant force is relatively small compared to the forces which may be required to move relatively'heavymachine components in the gear finishing operation. In order to obtain a measurement of the actual resultant force acting directly between the engaged portions of the gear and hone irrespective of the magnitude of the force which may be applied to the relatively heavy machine components, means are provided for obtaining a direct measurement of the resultant force available for determining the actual pressure contact conditions between the teeth of the gear and hone. By observing the magnitude of the total motive force applied at this time, and maintaining this total motive force constant during the gear honing operation, the much smaller resultant force between the gearand honemay be'maintained accurately controlled values. Account is of course taken of mechanical advantages, if any, due for example to lever arms which may determine the actual force acting between the bone and gear.

In the present case a measuring device, conveniently in the form of a dial indicator, is provided for the purpose of determining wear as it takes place progressively on the hone. When a new hone is placed on the machine, the dial "indicator is'zeroed when the hone and gear are initially brought into tight mesh. Thereafter, the operator observes the action of the honing tool and gear, and when the hone has worn sufficiently so that the crests of the hone teeth are bottomed in the spaces between the teeth of the work gear, the amount of reduction in center distance between the gear and hone is noted by observing the dial indicator reading at this time. This is taken to be the amount of center distance reduction at which further hone dressing operations are required. Thereafter, signaling means on the machine are set so that when this predetermined reduction in center distance is approached, a signal light goes on which indicates to the operator that the hone requires dressing or replacement. Thus, after the first usage of the hone, it is thereafter unnecessary for the operator to observe the hone operation carefully so as to deterof force over that required to move the work or tool support and thus, available to establish the operating pressure conditions between the hone and gear.

Finally, according to another feature of the present invention, means are provided for re-establishing initial honing conditions whenever the hone has been dressed or replaced after undergoing a predetermined amount of wear. According to this feature of the invention the gear support occupies an initial or starting position when a gear thereon is in tight mesh with a honing tool in new or newly dressed position. In the specific embodiment of the invention, where the work gear is supported on a tilt table biased by fluid pressure to rock the table so as to provide a yielding force maintaining the gear in tight mesh with the bone, the starting position is preferably the position in which the table extends horizontally and the axis of the gear is located directly above the axis of the pivot mounting of the table.

- Alternatively of course, the starting position may be such that the axis occupied by successive gears moves from a position displaced slightly at one side of a vertical plane through the pivot axis of the table to a finishing position located a substantially equal distance at the opposite side of such plane. When the hone has undergone sufficient wear so that the crests of the teeth of the hone begin to bottom in the spaces between the teeth of the gear, an interference condition is approached and at this time the honing operation is sus pended while the hone is either dressed by removing material from its outside diameter, or if it is sufficiently worn, the hone may be replaced. Thereafter, the hone support is advanced tobring the hone into engagement with a work gear and to move the work gear rearwardly so as to cause the work support, and specifically in the present case, the tilt table, to again assume the initial or starting position. This operation is preferably carried out automatically by a motor which advances the hone support to cause engagement'between the hone and work gear and thereafter to move the work gear to rock the tilt table to startingposition. A limit switch actuated by the work support when it is moved into its starting position is actuated to terminate operation of the motor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified perspective view of a gear honing machine to which the present invention is applied.

FIG. 2 is a simplified diagrammatic view illustrating the relationship between machine components.

FIG. 3 is an enlarged fragmentary elevational view of the wear and pressure measuring structure.

FIG. 4 is a side elevational view of the structure shown in FIG. 3.

DETAILED DESCRIPTION Referring first to FIGS. 1 and 2 the gear honing machine comprises a frame 10 at the front of which there is mounted a tilt table 12 having head and tail stocks 14 for supporting a work piece W. The stocks 14 provide spindle means indicated at 16 mounting the work gear W for rotation on a horizontal axis. The tilt table 12 is pivoted to the frame by pivot means 18, the axis of which is mounted substantially beneath the axis of the work spindle means 16.

Carried by the frame 10 is a fluid pressure piston and cylinder device 20 having a piston therein and a piston rod connected thereto, the upper portion of the piston rod being indicated at 22 and being connected to the forwardly extending end of the tilt table 12 as best illustrated in FIG. 2. The lower end of the piston rod indicated at 24, extends below the cylinder and performs a number of actions which will subsequently be described. In FIG. 2 however, the downwardly extending portion 24 of the piston rod is shown diagrammatically as actuating a limit switch LS1.

Located on the frame 10 in rear of the work supporting tilt table 12 is a sub-slide 26 guidedly Supported on ways 28 and additionally supported on a slideway 30. The movement thus provided for the sub-slide 26 is horizontal and parallel to the axes of the pivot support 18 and the axis of the work spindle means 16. Suitable means are provided for effecting back and forth traverse of the sub-slide 26 so as to distribute honing action longitudinally of the work gear W from one side to the other, or from end to end of the teeth thereof.

Mounted on the sub-slide 26 for horizontal movement to the right and left as seen in FIG. 2 is a hone slide 32. Power means including a motor 34 connected by a belt 36 and gear reduction means 38 to an adjusting screw 40 is provided. The screw 40 is engaged in a nut 42 carried by the sub-slide 26 and it will be observed that operation of the motor will effect adjusting movement of the hone slide 32 toward or away from the work support.

Carried at the front of the hone slide 32 is a hone support 44 which is mounted for adjustment thereon about a horizontal axis perpendicular to and intersecting the axes of the hone H and the work gear W. In FIG. 2 the hone support is shown with its axis extending horizontally for simplicity, but in FIG. 1 it will be apparent that the hone support has been angularly adjusted since the hone drive motor 46 is shown as extending at an angle to the horizontal. Drive means interconnect the motor 46 and the hone H may take the form of a belt concealed by cover 48. Means for angularly adjusting the hone support include circular guide means including a pilot (not shown), and the hone support will be clamped in adjusted position on the forward end of the hone slide. 4

With the structure as so far described, one of the important features of the present invention may now be described.

When an initial setup is made a hone in new condition or newly redressed is mounted on the hone spindle means 52 and the first of a succession or work gears W is mounted on the work spindle means 16. At this time it may be assumed that the hone slide 32 is retracted to g the left as seen in FIG. 2, at which position the hone may be dressed or a new hone mounted on the hone spindle means 52 if required. The motor 34 is now energized to operate the screw 40 to advance the slide 32 to the right as seen in FIG. 2. The hone will of course engage in meshed relation with the work gear W. It may be assumed that pressure in the cylinder 20 biases the tilt table 12 in a counterclockwise direction. Power advance of the slide 32 will cause the tilt table 12 to rock in a clockwise direction about the axis of pivot mounting 18 until the tilt table reaches a predetermined desired initial or starting position. At this time the piston rod will be moved downwardly and the lower end 24 thereof will operate limit switch LS1 to de-energize the motor 34.

As previously indicated, the limit switch LS1 is fixedly mounted so that when operated the tilt table 12 occupies its predetermined or initial starting position. This position, also as previously indicated, may be that in which the axes of spindle means 16 and the pivot means 18 are in vertical alignment or it may be slightly displaced from this position. For example, the initial setup may be such that during tilting movement of the table 12 occasioned by wear of the hone during the honing of a succession of gears, the axis of the spindle means 16 will pass through the vertical plane occupied by the pivot mounting 18 at a time when the hone has undergone approximately half of the wear which is permitted between redressing operations.

In any case, after replacement of a hone or dressing of a hone, the machine is again placed in its initial setup position simply by initiating operation of the motor 34 which moves both the hone and the work to setup position. The hone remains in this position until redressing or replacement is required, but the tilt table moves counterclockwise as a multiplicity of work pieces are honed, due to the action of the piston and cylinder device 20 which maintains the hone and work in tight mesh under predetermined pressure conditions.

Reference is now made to FIGS. 2 and 3 which illustrate the structure associated with the lower end of the cylinder 20 from which the lower portion 24 of the piston rod extends. Secured to the lower end 24 of the piston rod is a cross-head 56. Fixedly secured to a mounting plate 58 is a limit switch LS1 having a plunger 60 actuated by a lever 62 pivoted as indicatd at 64 to an arm 66 fixed to the support plate 58. An actuating pin 68 extends through a guide tube 70 in housing 72 carried by the mounting plate 58 and when the tilt table 12 reaches the predetermined starting position, the

lower end 24 of the piston rod engages the pin 68 which rocks the lever 62 to actuate limit switch LS1, thus terminating operation of the motor 34.

MEASUREMENT OF BONE WEAR The cross-head 56 which is fixedly secured to the lower end 24 of the piston rod includes a laterally extending arm 76 carrying an adjustable abutment screw 78 which in turn engages the lower end of an actuating pin 80. Carried by a bracket 82 fixedly mounted on the plate 58 is a dial indicator 84 having an actuating plunger 86 extending to the left as seen in FIG. 3. Pivoted to the bracket 82 as indicated at 88 is a dog 90 having a lower horizontal surface 92 engageable by the upper end of the pin and a generally vertical surface 94 engageable by the end of the actuating plunger 86.

It will be observed that in the specific embodiment of the invention illustrated the line of the action of the plunger 86 is separated from the axis of the pivot mounting of the dog a somewhat greater distance than separates the axis of the pivot mounting from the line of action of the pin 80. If these distances are properly selected in accordance with the distance between the line of action of the piston 22,24 and the axis of the pivot mounting 18, which mounts the tilt table 12 to the frame 10, and the spacing of the axis of the spindle means 16 mounting the work gear W about the axis of pivot mounting 18, then the dial indicator 84 may read directly in terms of movement of the work gear W toward the hone l-l. Of course, if these distances do not bear the same relationship to each other, it may be necessary to convert the actual readings of the dial indicator into terms of displacement of the work gear, and to provide a dial on the indicator which reads in terms of gear displacement, rather than actual movement of the indicator plunger 86.

In operation of the machine and taking advantage of the indicator 84 for one of its intended purposes, the first of a succession of gears mounted on the machine and i a hone in new or newly dressed condition is meshed with the work gear and the parts adjustedinto the initial or starting position as previously described. At'this time the dial indicator is zeroed and operation of the machine commenced. Normally, machines of this type include automatic loading and unloading mechanism so that the machine undergoes a succession of cycles in which individual work gears are loaded in the machine, honed, withdrawn from the machine, and the following gear" automatically loaded into position. During this time, and particularly during the initial cycling of the machine, the operator will carefully observe the coaction between the hone and succession of work gears. During this time material is removed from the teeth of the hone and the honing operation of the succession of gears is accompanied by tilting motion of the table 12 from its initial position counterclockwise to maintain each of the succession of gears in tight mesh with the hone. Eventually, due to wear of the teeth of the hone, the crests of the hone teeth begin to bottom in the spaces between the teeth of the work gear. This condition, which may be termed'an interference condition, is undesirable and calls for dressing the hone by removing a predetermined amount of material from its outside diameter, or replacing it with a new hone, if the hone is sufficiently worn.

The reading of the dial indicator when the crests of the teeth of the hone begin to bottom in the tooth spaces of the gear, indicates the range of acceptable movement of the tilt table from its predetermined and repeatedly reset starting position to the position at which hone dressing or replacement is required. During subsequent honing cycles between successive hone dressing or replacement steps, it will not be necessary for the operator to carefully observe the condition of the gear and hone, but only to payattention to the reading on the indicator which indicates the amount which the tilt table has rocked during this particular succession of gears. When the indicator reading approaches that corresponding to the predetermined table position at which hone dressing or replacement is required,-the operator can stop automatic cycling and redress or replace the hone.

SIGNAL RESPONSIVE TO HONE WEAR The foregoing lends itself to a further improvement in automatic operation in which signal means such for example as a signal light (not shown) is provided on the machine which is adapted to be actuated when the tilt table has moved through its permissible range of movement and hence, calls for hone redressing or replacement. The signal light is connected to a limit switch LS2 which is adapted to be actuated by an adjustable abutment 96 carried on an arm of the cross-head 76.

When the piston has moved upwardly so as to tilt the tilt table from its initial or starting position to the position calling for hone dressing or replacement, the abutment 96 may be adjusted so that in this position it trips the limit switch LS2 and lights the signal light. Accordingly, after the hone has been dressed or replaced and the hone slide advanced to reposition the tilt table in starting position, resulting in downward movement of the piston in the cylinder 20, the abutment 96 will be spaced below the limit switch LS2 by the required amount so that when the tilt table, during the next succession of gear finishing operations, has worn material from the hone to a degree to require hone dressing or replacement, the abutment 96 will trip limit switch LS2 and light the signal light.

Obviously, instead of lighting the signal light, the switch LS2 may be suitably connected into the machine circuitry so as to terminate automatic machine operation until the hone has been dressed or replaced.

MEASUREMENT OF HONING PRESSURE ln gear honing machines a relatively small force acting directly between the gear hone and the work gear is desirable. For example, a honing force of between 20 and 30 pounds if typical. It is to be understood that this force is the overall force and no attempt is made to accurately determine the actual pressure between the inclined surfaces of the teeth.

Determining the amount of this force and controlling it accurately is rendered difficult due to the fact that the honing machine includes relatively heavy and massive components which require forces many times greater than the resultant honing force to effect movement. For example, in the present machine it is apparent that the honing force which determines the actual force applied horizontally between the hone H and the work gear W, is accomplished by lifting the table 12 or at least by rocking it about a pivot axis so that a substantial lifting force is required.

In order to clarify the terms used herein, the total lifting force applied by the piston and cylinder device 20 is referred to as the motive force. It will be understood that a large proportion of'this force is required to overcome the weight and resistance to movement of the tilt table. Accordingly, the honing force which is the horizontal force applied directly to the bone by the work gear W is in general equal to the motive force less that portion thereof necessary to effect unopposed horizontal movement of the hone.

in order to determine this honing force, the machine is provided with a calibrated leaf spring having a lower inclined portion as shown adapted to be engaged by a pin 102 carried by the dog 90. As illustrated, the pin 102 is spaced from the axis of the pivot connection 88 ofthe dog in a position to move clockwise upon upward movement of the piston and generally perpendicular to the lower inclined portion of the leaf spring. Conveniently, the leaf spring is formed by providing a slot 104 in a plate 106 which is pivoted on a pin 108. The plate 106, in the operating position best illustrated in FIG. 3, is retained against movement by a movable lug 110 held in position by a clamping screw 112.

With the parts in the relationship illustrated in FIG. 3, and with either the work gear or the hone, or both, removed from the machine, pressure is applied to the cylinder 20 in an amount sufficient to move the piston upwardly until the pin 102 just engages the spring 100.

The spring is dimensioned such that at this time the shoulder 94 of the dog 90 will have engaged the plunger 86 of the indicator and the indicator needle will be displaced to an intermediate position. At this time the dial indicator is zeroed and the pressure of fluid within the cylinder is increased to obtain a predetermined displacement of the indicator needle.

The spring 100 thus opposes an increasing resistance to upward movement of the piston and the spring will have been calibrated so that any reading obtained on the dial indicator corresponds to an excess of force applied by the piston and cylinder device 20 over that required to effect unopposed upward movement of the table and hence, unopposed movement of the work gear W toward the hone. Thus, the indicator reading may be converted directly into a honing force, taking into account of course the spring rate as well as the proportions of motion transmitting elements such for .example as the lever arms of movement of the pin 102 and surfaces 92 and 94 of the dog, and the effective lever arms of the axis of the gear and the point of application of lifting force to the table with respect to the pivot mounting thereof. Having once established this relationship, dial indicator readings may be tabulated directly in terms of honing pressure measured in pounds. Accordingly, any particular desired honing pressure when observed may be co-related to the observed pressure existing in the piston and cylinder device 20 and of course, the desired honing pressure may thereafter be obtained by maintaining pressure of fluid within the cylinder 20 at the required value.

Of course, during the honing operation in which upward or tilting movement of the table is opposed only by engagement of the gear W and the hone H, the lug 110 is swung from the position best illustrated in FIG. 4 to permit free swinging movement of the spring plate 106.

As previously stated, certain features of the present invention are intended primarily for use in gear honing, in which the honing operation results in appreciable continuous wear of the honing tool. However, other features of the invention are applicable to gear shaving, gear rolling, gear bumishing, etc. Thus for example, the arrangement which permits determination of the actual operating forces acting directly between the tool and work piece have utility not limited to honing.

What I claim as my invention is:

l. A gear honing machine comprising a frame,

a work table pivoted to said frame for tilting movement about a horizontal axis,

means on said table including spindle means mounting a work gear for rotation about a horizontal axis substantially directly above the axis of tilting of said table to provide substantially horizontal movement of a work gear upon tilting of said table,

a sub-slide on said frame mounted for movement thereon in a direction parallel to the axis of rotation of said spindle means,

a hone slide mounted on said sub-slide for movement thereon perpendicular to the axis of said spindle means,

a hone support on said hone slide including spindle means mounting a hone for rotation in mesh with a work gear, at one side thereof,

means for driving one of said spindle means in rota tion,

means for reciprocating said sub-slide on said frame,

means for applying an adjustable motive force to tilt said table and to provide a resultant force acting directly between the hone and work gear,

hone adjusting means for moving said hone slide to move the hone toward and away from a work gear, whereby movement of said hone slide causes a hone carried thereby to engage a gear on said table and to rock the table,

means on said frame actuated by rocking of said table intora predetermined starting position to terminate operation of said hone adjusting means.

2. A machine as defined in claim 1 which comprises crossed axes setting means on said hone support for angularly adjusting the axes of the hone spindle means for different crossed axes relationships between the gear and hone.

3. A machine as defined in claim 2 in which the means for applying a motive force to the tilt table is a fluid piston and cylinder device.

4. A machine as defined in claim 3 in which the hone adjusting means comprises an electric motor, and the means for terminating operation of said hone adjusting means comprises a switch in circuit with said motor.

5. A machine as defined in claim 4 in which the predetermined starting position of said table is a horizontal position thereof wherein the axis of the work gear is substantially directly above the tilt axis of said table.

6. A gear finishing machine comprising a frame,

a tool support on said frame including a spindle for mounting a gear-like tool for rotation,

a work support on said frame including a spindle for mounting a work gear in mesh with a tool carried by the spindle,

means for driving one of said spindles in rotation,

one of said supports being movable,

and means mounting said movable support on said frame for movement toward and away from the other of said supports,

adjustable power means acting between said frame and said movable support for applying a motive force to said movable support in a direction to move said one support toward the other support and to establish a resultant force acting directly between a tool and gear carried by said spindles,

and means for measuring the value of said resultant force independent of the value of said motive force.

7. A machine as defined in claim 6 which comprises a gear-like hone on one of said spindles, and means for measuring the variation in position of the movable support under tight mesh conditions as a result of hone wear.

8. A machine as defined in claim 7 in which the means for measuring variation in position of the movable support comprises a member movable in accordance with movement of said movable support on said frame, and a sensing device for sensing the position of said member.

9. A machine as defined in claim 8 in which the means for measuring the value of the resultant force acting between the gear and tool comprises calibrated resilient means opposing movement of said member, said sensing device providing a reading of displacement of said member against the action of said resilient means as a measurement of such resultant force.

10. A machine as defined in claim 9 in which said cal- V ibrated resilient means is movable into and out of an operative position in which, in the absence of engagement between a gear and tool on said spindles, said resilient means together with said sensing device affords a direct reading of the resultant force acting between a tool and gear on said spindles when said resilient means is out of operative position.

11. A gear honing machine comprising a rotary gear support,

a rotary hone support,

means for driving one of said supports in rotation,

means for adjusting one of said supports into different fixed operating positions to accommodate different sizes of gears and bones, and to compensate for hone wear during honing of a multiplicity of gears,

yieldable means for biasing the other support toward said one support to establish honing pressure between a gear and a hone on said supports, said other support having a starting position determined by engagement between a work gear in mesh with a gear-like hone in new or dressed condition,

and means for sensing the successive positions of said other support due towear on the hone.

12. A machine as defined in claim 11 comprising power means for moving said one support toward said other support, whereby upon mounting a new or newly dressed hone in the machine, actuation of said power means will move said one support directly and through engagement between the gear and hone will also move said other support toward the aforesaid starting position thereof,

and meansrespo ns ive to movement of said other support into starting position to stop said power means and to stop movement of said other support in starting position.

13. A machine as defined in claim 11, further comprising:

signal means,

and adjustable signal actuating means operable by movement of said other support due to hone wear through a range sufficient to cause approach to a condition of interference between the bone and gear.

14. A machine as defined in claim 13, further comprising:

power means for moving said one support toward said other support, whereby upon mounting a new or newly dressed hone in the machine, actuation of said power means will move said one support directly and through engagement between the hone and a gear will also move said other support toward the aforesaid starting position thereof,

and means responsive to movement of said other support to starting position to stop said power means and stop movement of said other support in starting position.

15. A machine as defined in claim 14 in which the means responsive to movement of said other support is adjustable to return said other support after replacement or dressing of a hone to the same starting position.

16. A machine as defined in claim 14 in which said one support is the support for the hone and said other support is the support for the gear.

17. A machine as defined in claim 12 comprising in addition calibrated resilient means selectively movable into and out of position to oppose movement of said other support whereby with either the hone or gear or both removed from the machine, sensed movement of said other support against said calibrated resilient means affords a direct indication of the resultant force determined by subtraction of the force necessary to initiate movement of said one support from the entire motive force applied thereto.

18. A gear finishing machine comprising a frame, a first rotary support carried by said frame having a fixed operating position, a second rotary support, a carrier for said second rotary support movable on said frame to move said second rotary support toward and away from said first rotary support, means for driving one of said supports in rotation, feed means operably connected between said frame and said carrier to apply a force to move said carrier to move a gear and gear-like tool on said rotary supports into tight mesh and to apply a predetermined force therebetween, a position indicator on said frame operable while a gear and tool on said supports are in tight mesh to indicate the position of said carrier, calibrated yieldable means on said frame opposing movement of said carrier in a direction to cause said rotary supports to approach, whereby movement of said carrier after its movement is opposed by said yieldable means in the absence of engagement between a gear and tool on said rotary supports is an indication of the force applied to said carrier in excess of that required to move it and hence of the force exerted between a gear and tool on said rotary supports.

19. A machine as defined in claim 18 in which said position indicator is a dial indicator.

20. A machine as defined in claim 18 in which said calibrated yieldable means is a spring, and said carrier has operably connected thereto for movement therewith an abutment engageable with said spring.

21. A machine as defined in claim 20 in which said spring is movable on said frame between an operative position in which it is engaged by said abutment to oppose feed movement of said carrier and an inoperative position in which it is not engaged by said abutment during gear finishing operation of said machine.

22. A machine as defined in claim 20 in which said position indicator is a dial indicator, and an arm pivoted to said frame having a portion engageable with said indicator, and a second portion carrying said abutment.

23. A machine as defined in claim 22 in which said spring is a leaf spring, and said abutment is a pin carried by said arm.

24. A machine as defined in claim 18 in which said carrier is pivoted to said frame in position such that swinging movement of said carrier causes substantially direct approach and separation between said rotary supports.

25. A gear honing machine comprising a frame, a rotary gear support on said frame, a rotary hone support on said frame, means for adjusting one of said supports on said frame into different fixed operating positions to accommodate different sizes of gears and hones in mesh and to provide for adjustment after replacement or trimming of a hone after predetermined wear, means for biasing the other support yieldably toward said one support to cause a gear and a hone on said supports to enter into tight mesh, said other support being movable Ell while the gear and hone are in tight mesh from a selected starting position while the hone is new or newly trimmed to a second position selected as a finishing position as the hone wears in which the hone requires trimming or replacement, and means for adjusting said one support toward said other support after replacement or trimming of a hone when said other support has reached finishing position to reposition said one support to a new position in which by engagement between the new or newly trimmed hone and work gear, said other support is moved to said selected starting position.

26. A machine as defined in claim 25, comprising signal means responsive to movement of said other support into finishing position. v

27. A machine as defined in claim 25 in which the means for adjusting said one support comprises motor means, and means responsive to movement of said other support into starting position to terminate operation of said motor means. 

1. A gear honing machine comprising a frame, a work table pivoted to said frame for tilting movement about a horizontal axis, means on said table including spindle means mounting a work gear for rotation about a horizontal axis substantially directly above the axis of tilting of said table to provide substantially horizontal movement of a work gear upon tilting of said table, a sub-slide on said frame mounted for movement thereon in a direction parallel to the axis of rotation of said spindle means, a hone slide mounted on said sub-slide for movement thereon perpendicular to the axis of said spindle means, a hone support on said hone slide including spindle means mounting a hone for rotation in mesh with a work gear, at one side thereof, means for driving one of said spindle means in rotation, means for reciprocating said sub-slide on said frame, means for applying an adjustable motive force to tilt said table and to provide a resultant force acting directly between the hone and work gear, hone adjusting means for moving said hone slide to move the hone toward and away from a work gear, whereby movement of said hone slide causes a hone carried thereby to engage a gear on said table and to rock the table, means on said frame actuated by rocking of said table into a predetermined starting position to terminate operation of said hone adjusting means.
 2. A machine as defined in claim 1 which comprises crossed axes setting means on said hone support for angularly adjusting the axes of the hone spindle means for different crossed axes relationships between the gear and hone.
 3. A machine as defined in claim 2 in which the means for applying a motive force to the tilt table is a fluid piston and cylinder device.
 4. A machine as defined in claim 3 in which the hone adjusting means comprises an electric motor, and the means for terminating operation of said hone adjusting means comprises a switch in circuit with said motor.
 5. A machine as defined in claim 4 in which the predetermined starting position of said table is a horizontal position thereof wherein the axis of the work gear is substantially directly above the tilt axis of said table.
 6. A gear finishing machine comprising a frame, a tool support on said frame including a spindle for mounting a gear-like tool for rotation, a work support on said frame including a spindle for mounting a work gear in mesh with a tool carried by the spindle, means for driving one of said spindles in rotation, one of said supports being movable, and means mounting said movable support on said frame for movement toward and away from the other of said supports, adjustable power means acting between said frame and said movable support for applying a motive force to said movable support in a direction to move said one support toward the other support and to establish a resultant force acting directly between a tool and gear carried by said spindles, and means for measuring the value of said resultant force independent of the value of said motive force.
 7. A machine as defined in claim 6 which comprises a gear-like hone on one of said spindles, and means for measuring the variation in position of the movable support under tight mesh conditions as a result of hone wear.
 8. A machine as defined in claim 7 in which the means for measuring variation in position of the movable support comprises a member movable in accordance with movement of said movable support on said frame, and a sensing device for sensing the position of said member.
 9. A machine as defined in claim 8 in which the means for measuring the value of the resultant force acting between the gear And tool comprises calibrated resilient means opposing movement of said member, said sensing device providing a reading of displacement of said member against the action of said resilient means as a measurement of such resultant force.
 10. A machine as defined in claim 9 in which said calibrated resilient means is movable into and out of an operative position in which, in the absence of engagement between a gear and tool on said spindles, said resilient means together with said sensing device affords a direct reading of the resultant force acting between a tool and gear on said spindles when said resilient means is out of operative position.
 11. A gear honing machine comprising a rotary gear support, a rotary hone support, means for driving one of said supports in rotation, means for adjusting one of said supports into different fixed operating positions to accommodate different sizes of gears and hones, and to compensate for hone wear during honing of a multiplicity of gears, yieldable means for biasing the other support toward said one support to establish honing pressure between a gear and a hone on said supports, said other support having a starting position determined by engagement between a work gear in mesh with a gear-like hone in new or dressed condition, and means for sensing the successive positions of said other support due to wear on the hone.
 12. A machine as defined in claim 11 comprising power means for moving said one support toward said other support, whereby upon mounting a new or newly dressed hone in the machine, actuation of said power means will move said one support directly and through engagement between the gear and hone will also move said other support toward the aforesaid starting position thereof, and means responsive to movement of said other support into starting position to stop said power means and to stop movement of said other support in starting position.
 13. A machine as defined in claim 11, further comprising: signal means, and adjustable signal actuating means operable by movement of said other support due to hone wear through a range sufficient to cause approach to a condition of interference between the hone and gear.
 14. A machine as defined in claim 13, further comprising: power means for moving said one support toward said other support, whereby upon mounting a new or newly dressed hone in the machine, actuation of said power means will move said one support directly and through engagement between the hone and a gear will also move said other support toward the aforesaid starting position thereof, and means responsive to movement of said other support to starting position to stop said power means and stop movement of said other support in starting position.
 15. A machine as defined in claim 14 in which the means responsive to movement of said other support is adjustable to return said other support after replacement or dressing of a hone to the same starting position.
 16. A machine as defined in claim 14 in which said one support is the support for the hone and said other support is the support for the gear.
 17. A machine as defined in claim 12 comprising in addition calibrated resilient means selectively movable into and out of position to oppose movement of said other support whereby with either the hone or gear or both removed from the machine, sensed movement of said other support against said calibrated resilient means affords a direct indication of the resultant force determined by subtraction of the force necessary to initiate movement of said one support from the entire motive force applied thereto.
 18. A gear finishing machine comprising a frame, a first rotary support carried by said frame having a fixed operating position, a second rotary support, a carrier for said second rotary support movable on said frame to move said second rotary support toward and away from said first rotary support, means for driving one of said supports in rotation, feed means operably connected between said frame and said carrier to apply a force to move said carrier to move a gear and gear-like tool on said rotary supports into tight mesh and to apply a predetermined force therebetween, a position indicator on said frame operable while a gear and tool on said supports are in tight mesh to indicate the position of said carrier, calibrated yieldable means on said frame opposing movement of said carrier in a direction to cause said rotary supports to approach, whereby movement of said carrier after its movement is opposed by said yieldable means in the absence of engagement between a gear and tool on said rotary supports is an indication of the force applied to said carrier in excess of that required to move it and hence of the force exerted between a gear and tool on said rotary supports.
 19. A machine as defined in claim 18 in which said position indicator is a dial indicator.
 20. A machine as defined in claim 18 in which said calibrated yieldable means is a spring, and said carrier has operably connected thereto for movement therewith an abutment engageable with said spring.
 21. A machine as defined in claim 20 in which said spring is movable on said frame between an operative position in which it is engaged by said abutment to oppose feed movement of said carrier and an inoperative position in which it is not engaged by said abutment during gear finishing operation of said machine.
 22. A machine as defined in claim 20 in which said position indicator is a dial indicator, and an arm pivoted to said frame having a portion engageable with said indicator, and a second portion carrying said abutment.
 23. A machine as defined in claim 22 in which said spring is a leaf spring, and said abutment is a pin carried by said arm.
 24. A machine as defined in claim 18 in which said carrier is pivoted to said frame in position such that swinging movement of said carrier causes substantially direct approach and separation between said rotary supports.
 25. A gear honing machine comprising a frame, a rotary gear support on said frame, a rotary hone support on said frame, means for adjusting one of said supports on said frame into different fixed operating positions to accommodate different sizes of gears and hones in mesh and to provide for adjustment after replacement or trimming of a hone after predetermined wear, means for biasing the other support yieldably toward said one support to cause a gear and a hone on said supports to enter into tight mesh, said other support being movable while the gear and hone are in tight mesh from a selected starting position while the hone is new or newly trimmed to a second position selected as a finishing position as the hone wears in which the hone requires trimming or replacement, and means for adjusting said one support toward said other support after replacement or trimming of a hone when said other support has reached finishing position to reposition said one support to a new position in which by engagement between the new or newly trimmed hone and work gear, said other support is moved to said selected starting position.
 26. A machine as defined in claim 25, comprising signal means responsive to movement of said other support into finishing position.
 27. A machine as defined in claim 25 in which the means for adjusting said one support comprises motor means, and means responsive to movement of said other support into starting position to terminate operation of said motor means. 